The weather gods finally cooperated and gave us a spectacular autumn day with no wind. I was fortunate in being able to take advantage of it, but I used a smooth rifle (smoothbore with sights, adjustable in this case) instead of a ML rifle. The gun is a T/C .56cal. Renegade SB (cap lock), which I got new a few years ago. In spite of that, its internals needed a bit of work and the sights were in need of adjustment, both windage and elevation. Since I wasn't shooting for record (lower back issues), I allowed myself to experiment with both powder charges and loading technique. I.e., I primarily used a patched .550" RB which I cast and weighed with 75gr GOEX.FFg. (Varying the charge up and down by 10gr. really had no effect that I could detect.)
I also monkeyed with that .550" RB and a 1/8" felt wad that I punched out and lubed yesterday (Duro Felt) + a thin over shot wad atop the RB. This was an abject failure as the RB's were all over the [right hand] target. Accuracy was so inconsistent that I didn't take ten shots at the pumpkins.
As I wasn't shooting for record, and since I had a bag of tow with me, I figured, why not try it (with an over shot wad) at least on some of the pumpkins on the lower, middlemost target. It worked OK, but the patched RB was consistently more accurate. Btw, I upped the powder charge to 80gr. since the tow loads were a bit looser in the bore.
Conclusions? Using a SB in a rifle match wasn't my smartest idea (insert your own witty phrase here). Second, the .550" RB + .011" -.012" patch ("Sew Classics" from Jo Ann Fabric) is a tight fit: Accuracy is pretty good with it, but it wouldn't be what I'd use if I needed a quick follow up shot or at a woods walk as it hold up the "walk." For that and almost the same accuracy, I'd use a .535" RB (My Lee mould casts @ .537" with pure Pb) and an appropriately thicker patch. Using tow wads may be worth exploring too, especially if you favor a PC/HC bare ball load. Lastly, those pumpkins got really small, really fast after I stapled them to my backer. They weren't easy @ 25 yd. (especially the middle one!) with a long gun, but even with a pistol @ 15 yd., they'd pose quite a challenge.
Good luck and good shooting!